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. Author manuscript; available in PMC: 2018 Sep 1.
Published in final edited form as: Mol Cancer Ther. 2017 Jun 15;16(9):1751–1764. doi: 10.1158/1535-7163.MCT-17-0040

Figure 6. Combination treatment inhibits growth in an Rb-positive leiomyosarcoma PDX line.

Figure 6

(A) Western blot analysis of 13 leiomyosarcoma PDX lines for G1 checkpoint proteins to select model for study. Four of the PDXs (PDX 18, 20, 21, 22) which were Rb-positive were chosen for further analysis. (B) Western blot analysis of Rb pathway proteins revealed stability across passages in untreated tumors. (C) Average PDX tumor volume (model #22) during treatment, (n=5 per arm for all). Each mouse in this study was implanted with the same passage of PDX#22 taken when the tumors reached the maximum size for sacrifice or the end of the experiment. Error bars represent SEM. (D) Mean fold change in PDX tumor volume between day 1 and day 25 (end of treatment). Error bars represent SEM. (E) Western blot of tumor samples showing indicated proteins using vinculin as a loading control. Phospho-Rb and cyclin D1 as a measure of palbociclib pharmacodynamics are significantly reduced in combination treated tumors, while total Rb levels remain high. Levels of CDK4 and CDK6 are relatively stable across all treatment groups. Error bars represent the standard deviation from the mean unless otherwise indicated. Pairwise comparisons were analyzed using multiple t-tests (one unpaired t-test per row).